Calipers



(No Model.)

J. N. PEAVEY, Jr.

GALIPERS.

No. 571,788. Patented Nov. 2.4, 1896.

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JOHN N. PEAVEY, JR., OF ASHLAND, NFV l'lAMPSlllRE.

CALIPERS.

SPECIFICATION forming part of Letters Patent No. 571,788, dated November 24, 1896.

Application filed May Z7, 1896. Serial No. 593,200. [do model.)

lo @ZZ whom it may concern,.-

Be it known that I, JOHN PEM/EL J r., a citizen of the United States, residing at Ashland, in the county of Grafton and State of New Hampshire, have invented certain new and useful Improvements in Calipers; and l do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the saine.

This invention relates to the pivot-joint of dividers, calipers, or like instruments, the object being to provide means whereby such instruments may be set to any desired measurement and firmly fixed at the joint.

The invention consists, essentially, in pivoting the legs of dividers independently to a suitable yoke and providing a 1aokand-pin ion mechanism connecting the legs and ad justing or controlling the same by one or more nuts threaded to a stud, as fully set forthin the following; specification and claims and clearly illustrated in the accompanying drawings, forming a part of the saine, of Which- Figure l is an elevation showing an instrument of the character above named provided With my improved joint, Fig. 2 being a broken edge view of a similar instrument provided With .my improved joint. Fig. 3 is a sectional elevation showing a pair of calipers having my improved joint as when partly open. Fig. i is an elevation of the retainingyoke within Which the legs of dividers or calipers are pivoted. Fig. 5 is a cross-section of the same, Fig. G being a plan view of same. Fig. .7 is an elevation of a threaded stud Within which is secured a rack for engaging the pinion-teeth with which the legs are supplied. Fig. S shows the threaded stud having the rack removed.

Similar referencedetters designate corresponding parts in all the views,

A represents the legs of my improved dividers or Calipers, and B is a yoke-piece, in which the legs are independently pivoted by the screws or rivets C. The yoke B is also provided With a rivet or screw, as shown at o, for preventing the extreme lower edges of said yoke from springing ont of place or spreading, 'the pertorations b', which have acentral location, being formed for this purpose.

Each leg A is provided at its top with spurteeth a', formed in a segment of a circle a, in which the leg-pivot C is concentric, and these teeth mesh with a rack D, having teeth d on each edge, said rack being rigidly secured Within a slot c, formed for the purpose in the lower portion of a threaded stud E, which rests in perforation h of the yoke B, said perforation having a smooth bore, so that said stud E may be free to move longitudinally therein Without being rotated, as the spurteeth a of the legs .A rest Within the slot e of the stud E, the rack l) being narrower than the said stud.

Rectangular openings b2 are formed one in each side of the yoke B, in which rests a nut F, which is thread ed to iit the stud E, and by rotating said nut the stud is raised or lowered within the perforation of the yoke, Which causes the legs to move by engagement with the teeth of the rack D, an upward movement of the stud E causing the legs to close, and vice versa.

G is a check-nut threaded to stud E above the yoke B, which may be turned down hard onto the top of said yoke as a. means of more firmly setting the joint at a given measure ment after the legs A have been set, but this cheek-nut is by no means essential or in any Way an important feature of my invention.

The top of the yoke B maybe made thicker by forming a boss or hub b3 at the point where the perforation I) is formed, as seen in Figs. Il and (5, so as to provide a longer bearing for the stud E.

The yoke ll is preferably provided with curvilinear end portions D", whose inner snrfaces correspond with the circular portion a of the top of the legs A, in which the teeth a are formed, and a curvilinear slot a2 is formed in each leg for the reception of said curved portions b4 of the yoke, which forms for each leg an interlocking joint and keeps out considerable dust and dirt.

The instrument may beinade so as to be readily converted into either dividers or calipers by forming each leg short and providing means for connecting detachable extensions, as in the case of ordinary dividers, or the short portion of the legs may be formed partly TOO hollow and provided with a slot, as seen at ai in Fig. 2, the ond of the leg being tapered slightly and provided with an extern al thread d4, to which a tapered nut II yniay be fitted, and after inserting either form of leg which may be required, as at A in Fig. 3, in the socket or hollow portion of the short leg of the instrument the nut II may be turned up and thus secure the two sections A A Iirrnly together. In place of an extension-leg a conimon lead-pencil may be placed in the short leg and secured in the same manner by the nut II. Y

Having described my improvements, what I claim isl. In dividers or calipers, an adjustable joint comprising independently-pivoted legs provided with a segment of a spur-pinion within Whieh the pivot of each is concentric, a threaded stud adapted for longitudinal movement between the pinion portions of said legs, a double rack secured to said stud and engaging the pinions of said legs, and a nut threaded to stud for adj Listing the same.

2. In dividers or calipers, an adjustable joint comprising a yoke-piece carrying independently-pivotal legs provided with a segpendently-pivoted legs havin g each a segment u of a spur-pinion Within which the pivot is eeneentric, a threaded stud adapted for longitudinal movement between the pinion portions of said legs, a double rack engaging the pinions of said legs and secured to said stud.y and a pair of nuts threaded to said stud one resting in slots formed for the purpose in the yoke and the other placed above and adapted to be turned down upon said yoke, all subn stantially for the purpose set forth.

In testimony whereof I afiix my signature in presence of two Witnesses.

JOHN N. PEAVEY, Jn. fitnessesz J. B. THURsToN, Gno. II. WARREN. 

